package wc;
import java.io.IOException;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Mapper;
//泛型 k1 v1 k2 v2
public class WordCountMapper extends  Mapper<LongWritable, Text, Text, IntWritable> {
    @Override
    protected void map(LongWritable key1, Text value1, Context context)
        throws IOException, InterruptedException{
        /*
        *context表示Mapper的上下文
        * 上文: HDFS
        * 下文: Mapper
         */
        //数据: I love Beijing
        String data = value1.toString();
        //分词
        String [] words =data.split(" ");
        //输出 k2 v2
        for (String w:words){
            context.write(new Text(w), new IntWritable(1));
        }
    }
}